Which are the proportions to substitute butter in a cake for oil?

liquefy the butter and use the same measurements of liquefied butter as recipe calls for oil.

Butter has 10% water content, so you need to increase it slightly. Add about 1 tablespoon per stick more than the oil. It would turn out ok either way. I do that all the time, in fact I'm eating some leftover cake right now, made with melted butter and milk instead of the usual recipe on the box.

I'm glad I re-read some of my answers.

In a recipe cake, the butter is usually whipped, not melted. This adds more texture than oil would. So the answer is, you can add oil instead of butter in a recipe with melted butter, but not with softened, whipped butter. Of course, you could always try it, the cake would still be eadible, if slightly imperfect.

I have literally baked millions of cakes in my life. I used to bake for a home industry in South Africa, and all our cakes had oil instead of butter in the recipes, because the cakes had a longer shelf life when made with oil. The texture was also moister.

When converting a recipe that had butter in its ingredients, I used a rule of thumb, and it always works:

one kilogram of butter is roughly equal to one litre of oil.

That means that 100 grams of butter can be replaced by 100 millilitres of oil. Don´t kill yourself trying to figure out what percentage water content the butter has. There is not much difference - when the butter is melted, it is like oil.

Fruits. Bananas are my favorite. btw did you know that tomatoes are the #1 selling fruits? true beans

fruit grows on forest or vines and fruit and vegetables grow in the land.